Format

Send to

Choose Destination
Am J Clin Nutr. 2003 Feb;77(2):399-405.

A novel dual radio- and stable-isotope method for measuring calcium absorption in humans: comparison with the whole-body radioisotope retention method.

Author information

1
Research Department of Human Nutrition, The Royal Veterinary and Agricultural University, Frederiksberg, Denmark.

Abstract

BACKGROUND:

Dietary calcium absorption can be determined only with the use of isotope techniques. Currently used isotope techniques require exclusive equipment or are not true tracer approaches.

OBJECTIVE:

The objective was to compare a dual-isotope method combining radioisotopes and stable isotopes with a whole-body radioisotope retention method for measuring calcium absorption.

DESIGN:

Seven healthy adults aged 21-27 y consumed a test meal containing 63 +/- 14 (macro x +/- SD) mg Ca together with a water solution of (47)Ca (0.11 MBq). One hour after ingestion, 18 mg (44)Ca was administered intravenously. All feces and urine were collected for 5 and 6 d, respectively. Calcium absorption was estimated from whole-body retention of the radioisotope 12 times over 3 wk after ingestion and from the excretion of (47)Ca and (44)Ca in a 24-h urine sample collected on day 2. (44)Ca in urine was determined by inductively coupled plasma mass spectrometry.

RESULTS:

Mean (+/- SD) calcium absorption was 75 +/- 9% with the dual-isotope method and was 74 +/- 8% with the whole-body radioisotope retention method. There was a high degree of agreement between the methods.

CONCLUSION:

The dual-isotope method is a valid approach for measuring calcium absorption from a single meal.

PMID:
12540400
DOI:
10.1093/ajcn/77.2.399
[Indexed for MEDLINE]

Supplemental Content

Full text links

Icon for Silverchair Information Systems
Loading ...
Support Center